The present invention relates a semiconductor device, in particular to a semiconductor device with improved heat radiating property.
Due to the development of the process technology of semiconductor devices in recent years, the process rule and the size of the semiconductor device are becoming smaller and smaller. Moreover, the demands on the semiconductor device for more increased integration and more increased output power are becoming more and more stronger.
It is thus increasing more desired to improve the radiation of heat from semiconductor chips contained in the semiconductor device, in order to prevent failure in operation, and damages to the semiconductor device due to the heat generated by the semiconductor chip, and the poor heat radiation of the semiconductor device packages.
To meet with the demands, and to prevent the bending of a substrate due to the heat generated by the semiconductor chips, Japanese Patent Kokai Publication No. H11-186430 discloses a semiconductor device comprising a semiconductor chip having a plurality of electrodes, a glass epoxy resin substrate on which the semiconductor chip is mounted, and which has leads connected to the respective electrodes, external electrodes provided on the conductor patterns electrically connected to the leads, wherein slits are provided in the glass epoxy resin substrate.
Japanese Patent Kokai Publication No. 2001-168139 discloses a structure in which a plurality of columnar protrusion electrodes are provided on the peripheral parts of the lower surface of the silicon substrate, grooves are provided to extend along each side of the silicon substrate, at portions corresponding to the protrusion electrodes on each side, and inside of the protrusion electrodes, on the upper surface of the silicon substrate, in order to relax stress due to thermal expansion, and to prevent cracks in the protruding electrodes and connecting terminals.
In the conventional semiconductor devices of such structures, it is becoming more difficult to ensure radiation of heat from the lower surface of the substrate on which a semiconductor chip is mounted, and in which a particularly greater amount of heat is generated.
Because the heat radiation property is not sufficient, the electrical property may be degraded, and malfunction may be caused.